Continued expansion and intensification of large-scale swine operations in
the United States have brought about some important environmental, agricultural,
and public-health issues. Waste-management practices for these operations
commonly utilize open earthen lagoons, ponds, or slurry tanks for the temporary
storage of manure in a liquefied form, which is subsequently applied as
fertilizer on agricultural fields. This practice, under certain conditions, may
contaminate the ground and surface water in the surrounding area. Research on
the direct and indirect human-health effects of this contamination is very
limited. We conducted a pilot investigation on the chemical and microbial
constituents of ground and surface water proximal to large-scale swine
operations in the State of Iowa. We measured potential chemical (pesticides,
antibiotics, heavy metals, minerals, and nutrients) and microbial (Escherichia
coli, Salmonella sp., Enterococcus sp., Yersinia sp., Campylobacter
sp., Cryptosporidium parvum) contaminants that may be hazardous to
human health. The study accomplished its primary goal of obtaining a broad
profile of the chemical and microbial constituents of both ground and surface
water proximal to large-scale swine operations. We identified chemical
pollutants and zoonotic pathogens in the environment on and proximal to these
operations. However, the sample-collection sites were not in locations that
could pose a direct threat to human health. More research is needed to
accurately determine the level of risk, pathways of exposure, and critical
control points to avoid any potential exposure; follow-up investigations are
being considered in the near future.